Power generation for implantable devices

ABSTRACT

An implantable, rechargeable medical system comprised of an implanted device, a power storage device connected to the implantable device, and a charging device operatively connected to the electrical storage device. The charging device can be thermoelectric and have components for transferring thermal energy from an intracranial heat accumulator to an extra-cranial heat sink, for generating an electrical current from the thermal energy transfer, for charging the electrical storage device using the electrical current, for measuring power generation, usage and reserve levels, for measuring temperatures of the intracranial and extra-cranial components, for physically disrupting heat transfer and charging operations, and for generating signals relevant to the status of temperature and electricity transfer in relation to energy generation criteria. The system may also have long-range and short range wireless power harvesting capability as well as movement, and photovoltaic charging capability. Components may be dual purpose, being used for receiving wireless energy as well as for accomplishing other operations such as sensing or stimulating. Specialized accessories assist with providing enhanced wireless power charging.

This application claims priority to U.S. provisional application60/977,086 filed on Oct. 2, 2007 entitled “Systems and Methods forWireless Power”, 60/941,286 filed on Jun. 1, 2007 entitled “Systems andMethods for Wireless Power”, 60/941,287 field on Jun. 1, 2007 entitled“Power generation for implantable devices”, and co-pending applicationnot-yet-known filed on Jun. 2, 2008 entitled “Systems and Methods forWireless Power”, incorporated by reference herein.

The invention relates to providing energy to implantable devices andusing wireless energy which has been transmitted and energy derived fromnatural resources which are available in the patient's environment withan emphasis on utilization of RF energy, heat, light, and motion.

BACKGROUND

Implantable medical devices use electrical power to operate and providetherapies which can include monitoring and stimulation. When therapy isprovided or adjusted programmably, using an external patient controller,communication between the external and internal components of themedical system also requires power. An implantable device can monitorthe heart and alert the patient when an abnormal cardiac state occurs sothat they may seek intervention such as is described in U.S. Pat. No.6,609,023 and US20070016089, both to Fischell et al. The implantabledevice may also use this monitoring in delivering responsive therapysuch as pacing the heart, delivering a drug, or stimulating nerve tissueof the brain or body as described in U.S. Pat. No. 6,066,163, to John.

An implantable medical device can be a neurostimulation device whichperforms sensing and/or modulation of neural activity in the treatmentof, for example, epilepsy, motor, pain, psychiatric, mood, degenerative,and aged-related disorders. Neurostimulators can be located in thebrain, in the skull, or in the body. This last embodiment will requirethat electrode leads transverse the neck so that they can stimulatetheir intended neural targets within the brain. Vagal and cranial nervestimulators may also be used for therapies related to modulation of thebrain or body (as may occur directly or by way of an intervening neuraltarget). Implantable medical devices may be placed throughout the bodyto modulate the activity of different organs and biological processes,and include devices used in the provision of therapy for eatingdisorders, pain, migraine, and metabolic disorders such as diabetes. Asthe duration of sensing, processing, monitoring, and stimulationincreases the amount of power needed will also increase.

The reliability and longevity power source is major issue in operatingimplantable medical devices. Numerous advances have addressed powerrequirements including improvements in materials, (re-)charging methodsand technologies. Incorporation of dual battery paradigms has alsoprovided benefits since the two batteries can differ in characteristicsof energy storage, chemistry and power output capacities, in order to,for example, reach a compromise between high-energy output andsustainability. Implantable devices themselves have also been improvedwith features such as “sleep” and “low power” modes, where less energyis needed. Regardless of these improvements, all device operationsrequire power, including monitoring, processing of monitored data,stimulation, and communication with external devices.

A top reason for surgical removal of neurostimulators and other types ofimplanted devices is longevity of the power source. The need forsurgical removal of an entire implanted device traditionally occursbecause the battery is integrated into the device itself. Thisdesign-related issues can been addressed somewhat by having a separateskull-mounted power module which resides adjacent to theneuron-stimulator. However, surgery for selective removal/replacement ofthe power source is still invasive. Further, aside from issues ofreplacement, in ongoing use of implanted devices, more robust supply ofpower can provide improved therapy.

The current invention can incorporate a number of existing technologiessuch as U.S. Pat. No. 6,108,579, which discloses a battery-monitoringapparatus and method which includes features of tracking power usage,monitoring battery state, and displaying the estimated remaining life ofthe battery power source. U.S. Pat. No. 6,067,473 discloses abattery-monitoring apparatus and method which includes features ofproviding audible warnings of low battery life using both tones andpre-recorded verbal warnings of battery depletion. U.S. Pat. Nos.5,957,956, 5,697,956, 5,522,856, and US 20050021134 to Opie, and20050033382 to Single, disclose devices having features such as:relatively small mass and a minimal rate of power consumption; means foroptimizing current drain; improved shelf storage capacity; minimizingthe power requirements of battery power sources; temperature regulationof the power source; and dual battery implementation including use ofback-up battery to avoid power disruption. U.S. Pat. No. 7,127,293 toMacDonald describes a biothermal power source for implantable devicesand describes methods and materials which are suitable for use in thecurrent invention.

There is a need to provide a improved power supply means for rechargingof a power supply of an implantable medical device. Power supplyimprovements will allow improvements in the performance of the device.Recharging should not require recharging or replacement of the powersource in a manner which is unreliable or which is places an undueburden on the patient.

The invention provides improved power harvesting, generation and supplyand can rely upon naturally occurring sources of energy for at least aportion of its recharging needs. The invention also provides improvedpower harvesting of transmitted energy.

SUMMARY

A rechargeable power module for powering implantable devices includes apower storage module connected to said implantable device and a powercharging module operatively connected to the power storage module.

When the power charging module harnesses thermoelectric power, it has atleast a first thermal module and a second thermal module which providepower from a thermal gradient. These two modules can be intra-craniallyand extra-cranially disposed, respectively. The power charging module isconfigured for generating an electrical current from a thermal energygradient, and for charging said electrical storage module with saidelectrical current. The rechargeable power module also contains controlcircuitry for controlling power related operations, as well as chargemonitoring circuitry for monitoring rates and levels of charge of thepower storage module. The rechargeable power module may also containalerting circuitry for generating an alert signal whenever the extent towhich said electrical storage device is being charged with saidelectrical current falls below a specified value. A disruption modulecan break the physical connection between the first and second thermalmodules, or between the rechargeable power module an components of theimplanted device.

When the power charging module is a light-based power charging module,it can have at least one extra-cranially disposed surface that isconfigured for generating an electrical current from said light source(e.g., the sun or a synthetic means), and for charging said powerstorage device with said electrical current.

When the power charging module harnesses RF energy which is ambient andnaturally occurring, or which is actively transmitted by a transmitterdevice, then an antenna have at least one extra-cranially disposedsurface which is disposed for harnessing the RF energy. The energyharvesting antenna may also be used for transmission of data, and can bedisposed within a ferrule that resides within the skull, within the topside of a neurostimulator device disposed within the ferrule, or withinthe ferrule itself. When the implanted device is a neurological orcardiac device having leads, then one or more of these leads, as well assheaths which house the leads can be used, at least a portion of thetime, as an antenna for energy or data transmission or reception.

The power charging module may utilize external devices which altertemperature, light levels, magnetic or RF energy available forrecharging the power module.

The rechargeable power supply can also contain an alerting module forproviding energy-related alerts to a user and a historical charge modulewhich can be configured to generate an alert signal related to powerconsumption and harvesting. For example, an alert may be sent wheneverthe cumulative extent to which said electrical storage device is beingcharged with said electrical current falls below a specified value.

There are further provided methods for increasing wireless energyrecharging capabilities of the system including methods for increasingthe thermal gradient used to generate power and increasing the RF energyharvesting by increasing the RF energy which is available, received, andharvested by the implantable power harvesting device.

BRIEF DESCRIPTION OF THE DRAWINGS

Features of the invention will be described by reference to thespecification and to the following drawings, in which like numeralsrefer to like elements, and in which:

FIG. 1 shows a schematic diagram of one preferred implantable device foroperating using a rechargeable power system of this invention;

FIGS. 2A-2C shows three types of polarity reversing devices that may beused to harness power such as thermoelectric power by the system of FIG.1;

FIG. 3 shows a diagrammatic representation of a power harvesting modulewhich improves power harvesting related to thermal-based powergeneration;

FIGS. 4A-4C shows three types of thermal gradients which are applied tothermal modules, and which lead to improved energy harvesting using therouting device of the system of FIG. 3;

FIG. 5 shows an upper plot summarizing energy harvesting levels across a1 week interval, as well as average and current energy levels and showsa lower plot which can represent the energy harvested over the last 24hours, the energy harvested as function of time of day averaged over thelast week or month; and related plots such as target energy harvestinglevels as a function of time;

FIG. 6A-6B show schematic representations of skull mountedneurostimulator devices configured for generating power from a thermalgradient and for efficient thermal regulation of brain tissue; and,

FIG. 7 shows diagrammatic representation of a extra-cranially disposedenergy harvesting device which can be used for increasing the power thatis generated using methods generally known as well as those specific tothe present invention.

The present invention will be described in connection with a preferredembodiment. There is no intent to limit the invention to the embodimentsdescribed. The intent is to generalize the principles disclosed here toall alternatives, modifications, and equivalents as may be includedwithin the spirit and scope of the invention as disclosed within thefollowing specification and claims.

DETAILED DESCRIPTION

FIG. 1 is a block diagram of an implantable medical device 100 andrechargeable power system 10 which in a preferred embodiment functionsas a multi-modality charging system, but which may be restricted to asingle type of energy harvesting. The implantable device 100 may besimilar to many conventional generic implementations of neural orcardiac assistive devices, such as having a control module 102 whichimplements a therapy as defined in at least one control program 104. Thecontrol module 102 controls and communicates with all the other modulesof the device 100 in order to provide therapy as intended. Accordinglyunder control of the control module 102, the signal sensing andstimulation module 116 provides sensing of data, and stimulation,respectively, from probes 115 operatively positioned within the tissueof the patient (e.g. electrical, chemical, sonic, or optical probes) orwithin the device 100 itself (e.g., acceleration, level/tilt sensors, orthermal probes). Sensed data can be analyzed by the diagnostic module118 which can detect and/or quantify medically relevant events. Inresponse to the detection of medically relevant events, the controlmodule may responsively provide stimulation to a patient 6 or can issuean alert signal such as a sonic signal or a vibration using a probe 115which is a motor. Alternatively, the device 100 may send an alert signalusing a communication module 106 which can provide communication betweenthe implanted device 100 and an external patient device 125 such as apatient programmer device which is implemented in the form of apager-like device, with a display screen, LEDs, acoustic transducers,and buttons for patient input operations. In addition to memory storagesuch as RAM and EEPROM, the device 100 can have a storage/trend module112 which may contain a queriable database, and where information suchas parameter values, and historical records related to device operationand treatment may be stored. Temperature regulation (Heating or cooling)both of components within the device 100 or external probes 115 canoccur under the control of the temperature module 120. In onepreferential embodiment a temperature probe 115 is provided which allowscooling of the brain to occur by using a peltier-based probe configuredwith an extra-cranial heat sink and intracranial cooling surface. Apower module 108 may also be provided in order to provide operationsrelated to power management and monitoring, and for storing protocolsand parameter values which enable the control module 102 to communicateand control the rechargeable power system 10. Control conduits 150 a and150 b are comprised of at least one metallic or optical pathway whichprovides power and/or control signals to be communicated between thedevice 100 and the rechargeable power system 10.

The rechargeable power system 10 can harness power using at least one ofthermoelectric derived energy 300, solar derived energy 330,motion-based energy 332, RF harnessed energy 334 using far-field andmedium-field techniques, and energy harnessed from magnetic fields usingnear-field techniques 336. When utilizing far-field techniques themodules 334 can be based upon Powercast technology which provides forenergy harvesting of both ambient and transmitted energy, and mayinclude at least one antenna and associated harvesting circuitry. Somerelated technologies for transmission and reception, which can beutilized by the current invention have been filed by Powercast andinclude patent applications for example, US20070010295, US20060281435,US20060270440, US20060199620, US20060164866, and US20050104453. Somerelated technologies filed by eCoupled include, for example, InductiveCoil Assembly (U.S. Pat. No. 6,975,198; U.S. Pat. No. 7,116,200; US2004/0232845); Inductively Powered Apparatus (U.S. Pat. No. 7,118,240B2; U.S. Pat. Nos. 7,126,450; 7,132,918; US 2003/0214255); AdaptiveInductive Power Supply with Communication (US 2004/0130915); AdaptiveInductive Power Supply (US 2004/0130916); Adapter (US 2004/0150934);Inductively Powered Apparatus (US 2005/0127850; US 2005/0127849; US2005/0122059; US 2005/0122058. Splashpower has obtained patents such asU.S. Pat. No. 7,042,196. All these patents and patent applications areincorporated by reference herein and describe technologies which will begenerally understood herein as wireless power systems that relate to theinvention including RF- and near-field-induction-related wireless powertransmission and wireless power reception.

The energy harnessing modules 300, 330-336 are connected via the signalrouter 204 of the power management module 200 to control circuit 206 byleads 306 which provide electrical contact between the harnessingmodules 300, 300-336 and the power management module 200. Controlcircuit 206, in turn, is operatively connected to voltage regulator 208circuitry which includes safety and isolation components. The voltageregulator 208 provides direct current to at least one battery of a firstbattery 222 a, and a second battery 222 b of the energy storage module220. Although only 2 batteries are shown here, many batteries,capacitors, may be used in the power storage module, and these may bestored together, or in physically distinct regions of the device, andeven outside of the device. Although the electrical storage module 220would normally contain at least one battery 222 a,b which can berechargeable, other electrical storage devices can be used such astraditional capacitors or capacitors constructed of carbon,nanomaterials, or other suitable materials. The capacitors can becomprised of multilayer dielectric materials having capacitors andinsulators or other type of hybrid compositions (e.g., U.S. Pat. No.6,252,762 “Rechargeable hybrid battery/supercapacitor system”; U.S. Pat.No. 5,993,996 “Carbon supercapacitor electrode materials”; U.S. Pat. No.6,631,072 (“Charge storage device”); and U.S. Pat. No. 5,742,471(“Nanostructure multilayer dielectric materials for capacitors andinsulators”). The storage module 220 may be designed without a battery,as may occur, for example, if the battery of the implanted device 100 isto be primarily relied upon or if the device will rely upon externalenergy sources during its operation.

A power monitor 210 is connected to the storage module 220 and containssensors for monitoring the power level of batteries 222 as well as ratesof charge and discharge. The power monitor 210 can cause the powermanagement module 200 to issue an alert signal using the alert module110 of the implantable device 100 and is capable of providing a warningto a user when the power being generated, stored, or which is in reserveis inadequate. The probes 115 can be used to generate audible, visual,vibrator, or other type of alerts to provide warnings of low batterylife. An external patent programmer 125 can display a history of usage,recharging related historical information, and information related tothe remaining life of the battery, for example, as may be similar tothat shown in FIG. 5.

In a number of preferred embodiments the rechargeable power system 10relies upon the Seebeck effect which is also known as the“Peltier-Seebeck effect” or the “thermoelectric effect”. The Seebeckeffect is the direct conversion of thermal differentials to electricalvoltage. It is often produced using two junctions of dissimilartemperatures and metals. U.S. Pat. No. 5,565,763 (‘Thermoelectric methodand apparatus’) and U.S. Pat. No. 4,095,998 (‘Thermoelectric voltagegenerator’) describe implementing the Seebeck effect within energyproducing devices.

FIG. 1, shows thermoelectric module 300 that has at least a firstthermal module 302 and a second thermal module 304, which are connectedto the power management module 200 using leads 306. The electrical leads306 can be routed by a signal router 204 through a polarity reverser 212prior transmission of these signals to the control circuit module 206.The polarity reverser 212 is used to adjust for the case in which thetemperature of a first thermal module 302 is higher than the temperatureof a second thermal module 304, and also when the opposite is true. Thisadjustment is necessary since the polarity of the electric currentproduced the two situations will be reversed. If the polarity reversalcircuitry 212, did not exist then the electrical current produced by thethermoelectric module 300 would not be utilized by power managementmodule 200 in one of either the first or second situation. Variouspolarity circuit implementations are well known (e.g. see review in U.S.Pat. No. 7,127,293, [Bio-thermal power source for implantable devices]).

Although the device 100 of FIG. 1. may operate alone, when the device isimplemented as part of a network of implanted devices, power may begenerated, stored, and supplied in a distributed fashion usingcomponents which are either within the device 100 housing ordistributed. A device which is similar to identical to the BIONstimulation device, produced by Advanced Bionics may serve as the device100. When the device is implemented as a BION, at least one probe 115can serve to provide sensing or stimulation operations and the housingmay serve as a reference or ground source or as part of a bipolar probe.A portion of the BION device can serve as at least one antenna relatedto wireless power and data transmission. In a device with such smallmass and volume, it may be increasingly important to temporally separatecharging and non-charging related operations as can occur under controlof the control module 102 working in conjunction with the powermanagement module. Alternatively, the power transmission device can besynchronized with the BION's operations so that power transmissionoccurs only during intervals when the BION is not engaged in particularnon-charging treatment operations. When a network of BIONs are chargedby at least one wireless energy harvesting device, which may beincorporated into a rechargeable power supply, then either a master BIONmay control operations and allocations of wireless power, or any of theBIONS can communicate requests for or adjust operations related to powerharvesting.

FIG. 2A is a schematic diagram of a polarity reversal device 310 a thatcan be used to address opposite temperature differentials that resultforward and reverse currents (which can be implemented within thepolarity reversal module 212 of FIG. 1). When lead 306 a is negative,electrons flow to point 310, through diode 312, and then through path316. If the polarity is reversed due to a reversal of the relativetemperatures of thermal module 302 and 304, electrons will flow throughpath 306 b, through to point 318, through diode 314, and then throughpath 316. In either case, the temperature difference between the twothermal modules 302,304 will cause power generation. This feature isnecessary with biological thermal energy generation since the thermalmodules may unpredictably fluctuate both in terms of absolute levels andalso relative to each other. This circuit has previously been describedin the '293 application.

FIG. 2B shows that the polarity reversal device 310 b can also beimplemented in the form of a router which is guided by a temperaturesignal from sensors T1, T2 which are placed in the thermal modules andwhich communicate with temperature sensor module 216, which routeselectrical signals of paths 306 a and 306 b, to 320 and 316,respectively (or 320 and 316, respectively), depending upon whetherT1>T2 or T2>T1. Diodes 322 a and 322 b ensure that current flows in thecorrect directions.

FIG. 2C shows that the polarity reversal device 310 c can also be guidedby a voltage circuit that can be located in the control circuit module206 and that tests the voltage produced by connecting paths 306 a and306 b to different output paths 320 and 316 and determining whichcombination results in the maximum desired voltage and polarity. Againdiodes 322 a and 322 b ensure that current flows in the correctdirections.

FIG. 3 shows a signal router module 204 which is used to obtain currentin a number of different situations which may arise. The router module204 is connected by leads 306 to thermal modules 302A,B, and 304A,B.Normally thermal modules 302A and 304A serve as a first thermal moduleand a second thermal module and thereby form a first thermal pair 303A(which is formed conceptually and is not shown). The thermal pair may bepositioned in the patient so that 302A is normally more likely to bewarmer than 304A. Likewise thermal modules 302B and 304B form a secondthermal pair 303B (which is formed conceptually and is not shown). Inone embodiment a PNP layer 305A occurs between the first thermal module303A pair, while another PNP layer 305B occurs between second pair ofthermal modules 303B (as shown in FIGS. 4A-4B). The Table 1 shows threeexemplary conditions:

TABLE 1 Thermal Probe Condition 1 Condition 2 Condition 3 302A 38 35 36304A 35 38 35 302B 39 36 38 304B 36 39 39

Condition 1 shows the four thermal modules with relative temperaturesthat may occur in “normal” operation. Condition 2 shows temperaturesthat may occur in an “opposite” operation, where the polarity reversaldevices of FIG. 2A-C may be used. Condition 3 shows temperatures whichdiffer by only 1 degree and for which the second thermal pair wouldrequire a polarity inverter. In this last instance, using the signalrouter 204 of FIG. 3, the thermal modules can be re-assigned to form newthermal pairs, notably 302A can be paired with 302B to obtain adifference of 4 degrees (rather than 1), and 304A can be paired with304B to obtain 2 degrees (rather than 1).

In one embodiment, the voltage produced by thermal pair 1 is combinedwith the voltage produced by thermal pair 2, by circuitry in the powermanager 200. In another embodiment, the thermal modules within thermalpairs 1 and 2 are electronically fused so that 304A and 304B form the“cold” thermal pair (paths 306A and 306C are routed to 306 c′) and 302Aand 302B form the “hot” thermal pair (paths 306B and 306D are routed to306D′). In this case and the voltage produced is a function of theaverage differential between these two new functional modules. Combiningthe output voltages from the two thermal pairs should likely beequivalent to what is obtained by re-arranging the electrical paths toform 1 new “combination” thermal pair, but due to real world differencesone of these embodiments may perform slightly better than the other.Further, any performance differences between these two strategies can bea function of the ranges of temperature differential, and the powermanagement module 200 can select which strategy is used based uponselected ranges as well as other operational factors (e.g. increasedtemperature variability in one of the thermal modules).

The power management module 200 can be powered off of the energyharvesting modules 300, 330-336 or by the batteries 222. It is expectedthat when the temperature differential is greater than 2 degreesCelsius, electrical energy will be produced sufficiently to run thecontrol circuit 206. When the temperature differential is closer to 1degree Celsius, adequate temperature differential may still besufficient to provide adequate electron flow to control circuit 206.

FIGS. 4 a, 4 b, and 4 c show a thermal module having 8 thermal plateswhich can be configured to form a plurality of thermal pairs dependingupon the existing temperature differentials. Different thermal pairs arefunctionally created by rearranging electrical paths 306 so that thedifferent modules are functionally paired (form positive and negativegenerating components of a circuit). FIG. 4A shows how charge would flowfrom the left to the right of the thermal module 300′ when the plates onthe left side of the thermal module are hotter than the plates on theright. When the thermal gradient is reversed, the polarity reversalcircuits 310A-310C of FIG. 2A-FIG. 2C can be used. FIG. 4B shows aredistribution of the thermal pairs as a function of the thermalgradient being oriented 90 degrees from that seen in FIG. 4A. In thiscase, if the same charge pairs were used then there would not be muchthermoelectric output. However, by redefining the thermal modules thefunctional thermal gradient is increased. The thermal pairs created by302A and 304A, and 302B and 304B, are redefined as 302A and 302B and304A and 304B, in order to achieve this novel feature of the invention,wherein electrons travel through PN stack sections which are oriented at90 degrees to each other. In FIG. 4C, the thermal gradient runs from thetop of the thermal module to the bottom, and again, the thermal modulesare reorganized so that thermal pairs are created between the top 302′and bottom 302″ plates on the left, and right (304′ and 304″,respectively) side of the thermoelectric module (again an angle of 90degrees is used to establish a new orientation, but along a differentaxis of rotation).

Although a square configuration is shown, it is understood that themodules may be of various shapes and sizes, and may be adjustedaccording to the sites of implantation. Materials may also permit themodules to be constructed so that these have some degree of flexibility.While a single structure is shown in each of the FIGS. 4A-4C, thestructures may be imparted within a larger grid structure which may alsobe square or not. Although illustrated with respect to thermalgradients, and resulting electrical outputs, the same logic would beused in order to utilize the thermoelectric modules as Peltier-basedcooling devices, wherein applying currents to the different pairs wouldproduce different patterns of heating and cooling. Further, rather thanbeing restricted to thermoelectric generation, other modalities such aslight, sound (including ultrasound), motion (i.e. kinetic), and RFharvesting can be used with the systems and methods used by devicesshown in FIG. 1 trough FIG. 5 which depend upon displacement ofelectrical charge in the generation and storage of power.

The PN stacks 305 are here shown as thin layers sandwiched betweenthermoelectric pairs. The PN stacks can be comprised of several PNlayers which are oriented and organized in a number of fashions as iswell known. U.S. Pat. No. 6,207,887 (‘Miniature milliwatt electric powergenerator’) shows FIGS. 12 a and 12B indicating that use of smaller PNelements within the PN stacks produces higher output as a function ofthermal gradients, and accordingly the PN stacks utilized by theinvention may rely upon smaller elements.

Power Management, Reporting, and Control.

The power monitor 210 may use the memory 112 of the device 110 to createa historical record of power usage and consumption such as isgraphically shown in FIG. 5. FIG. 5 shows two exemplary plots of thedata that may be stored in module 112, as these may be displayed on theexternal patient programmer 125. The upper panel is a plot of a graphwhich shows a daily amount of wireless energy that was harvested overthe last 7-day period. The white bars represent the daily target whichthe patient is expected to meet, and these may be set, programmablydefined, or defined/adjusted, for example, as a function of time, powerusage, power generation, treatment needs, or user input. Additionally,the graph shows the cumulative amounts created over the entire week(with a change in units of energy) and the current amounts of power inthe power storage device. The black bars indicate actual energy created.By providing data about historical energy which was harvested or used,the patient 6 can gain understand about how daily activities alter powerharvesting and usage. The power monitor 210 can also be configured tosend alerts when energy harvesting increases above a specified level ordrops below a specified level, and a duration criterion can also beused, in order to assist patients in monitoring their energy usage.

In the lower panel of FIG. 5 a graph shows the cumulative powergenerated in the last 24 hour period (thin line) as well as theanticipated power which should have been created. Anticipated or target″power levels can, for example, have been previously determined by aphysician, or can have been computed based upon historical activity ofthe patient. In this case, the graph shows that from midnight until 6a.m. the power created was more than the target amount, while from 6 toaround noon, the power created was less. By the end of the day thepatient has generated a surplus amount of power compared to the targetamount (100%), and has well surpassed the target power generation level,which may be a minimum threshold limit value.

In order to keep the battery 222 from becoming discharged below aparticular level the alert module 110 can issue alerts when power levelsbecome critically low so that the patient will make certain that thebattery 222 is recharged in the near future. The alert module 110 mayalso be configured to shut down the device 10, or portions of the device10, or to limit operation to certain functions defined as a lower powerstate, when a particular critical level is reached so that there isenough energy to perform essential operations, such as operationsrelating to recharging the battery.

The re-chargeable power module 10 can be configured so that if thebatteries 222 become completely discharged, the module 10 can supplyemergency power to the device 100, or can initiate recharging operationsusing purely wireless power harvesting, if sufficient wireless powerbecomes available. This type of re-start operation can also comprisemarking the occurrence of a complete system shutdown in the storagemodule 112. When a minimum battery power is reached the storage modulemay store the time of the shut-down in flash-memory of module 112.Accordingly, upon re-start, the current time and date can bere-established using an external patient device 125, in order tocalculate how long the device was non-functional. Storing power‘shut-downs’ and ‘re-starts’ in the historical module 112, may also leadto the generation of an alert signal being sent by the alarm module 110,to a central station which the device communicates with using thecommunication module 106. This is important since if patients arenon-compliant with respect to ensuring sufficient energy harvesting,then the implanted device will not provide much therapeutic benefit.Unlike implantable devices which use very little power, when implantabledevices are configured to use more energy, it is important that thepatient is compliant in ensuring that energy harvesting is sufficientfor proper system operation.

In one instance, if the patient had not generated more power thanindicated by the “minimum power generation threshold level” by aselected time (e.g. 6 p.m.) then the alert module would have issued analert signal to the patient. Rather than displaying results for the last24 hours, the graph could have been computed upon charging patternscalculated for other prior periods such as the last week or month. Inthis manner the patient can learn about how daily activity affectstemperature around the thermal modules and can increase their ability tocharge the device as needed. In addition to power generation, other datacan be displayed including power usage, temperature of thermal modules,and differential temperatures of thermal pairs (as well as the pairsthat were created).

Alert signals can be generated in order to warn the patient when batterypower becomes lower than a specified amount, when the average rate ofpower consumption is more than the rate of power generation for aselected interval, when the slope of residual power by time has a valuethat is more than a selected level for a specified amount of time, aswell as numerous other characteristics related to charging, discharging,and residual power supply. Alerts can also be generated if thetemperature as recorded from thermal sensors 115 near thermal modules300 indicate that temperatures are outside of a normal range for anextended amount of time, for example, in a manner that is not beneficialto generating power in an expected fashion.

Power management and control provided by the power management module 200is needed for disentangling power related operations from otheroperations of the device 100. It is likely that in devices 100 whichutilize sensing, certain sensing operations should be halted, delayed,attenuated, or otherwise modified during a portion of the chargingoperations, and subsets of steps related to carrying out theseoperations, especially if the wireless harvesting includes near-fieldinduction transmitters. In devices 100 which utilize stimulation,certain stimulation operations should be halted, delayed, attenuated, orotherwise modified during a portion of the charging operations, andsubsets of steps related to carrying out these operations, especially ifthe wireless harvesting includes receiving energy which is above aspecified level. In devices 100 which utilize communication withexternal devices, certain communication operations should be halted,delayed, attenuated, or otherwise modified during a portion of thecharging operations, and subsets of steps related to carrying out theseoperations, especially if the data communications include alertingand/or transfer of diagnostic data related to an alert signal. Indevices 100 which utilize sensing, stimulation, or communication,transmission of wireless power or power harvesting operations should behalted, delayed, attenuated, or otherwise modified during a portion ofthe non-recharging operations, and subsets of steps related to carryingout these operations.

Additionally, the re-charging circuitry may be configured to work withthe sensing, stimulating, and communication circuitry so that variouscharging operations and related phenomena which are influence thesensing, stimulation, or communication subsystems of an implanted deviceare ignored, compensated for, or otherwise addressed by thesesubsystems, and there associated operations and algorithms. This type ofcompensation may occur, for example, using communication between thepower management module 200 and the sensing/stimulation 116,communication 106, or diagnostic 118 module. Selected non-chargingoperations can occur simultaneously with charging operations whenfilters and circuitry are provided to isolate the effects ofcharging-related operations and treatment related operations. Forexample electrical artifacts due to charging can be filtered out,subtracted, or made to occur in a time locked manner so that theartifacts occur in a controlled rather than spurious manner.

Thermal Issues of Energy Harvesting, Usage, Storage, and Stimulation.

Some preferred embodiments of implanted medical systems which includeNeurostimulators, ferrules, rechargeable power supplies, andthermal-cooling are shown in FIGS. 6A, 6B, and 7. In FIG. 6A the anextra-cranial receiver plate 350 a which approximately conforms to theskull may be used to disperse heat away from a skull mounted implantabledevice 100, which in this instance is a neurostimulator device whichresides within a ferrule 352. A thermal module 300 having a thermal pair302,304 which are separated by a PNP layer 305 supplies power to thedevice 100 using electrical conduits 306A, and 306B, which will supplyvoltage in one direction, or the other, depending upon whether one side302 of the thermoelectric module 300 (which receives or dissipatesenergy via the extra-cranial receiver plate 350 a) is hotter or coolerthan the other side 304 ((which receives or dissipates energy via theintracranial-cranial receiver plate 351). The power is communicated tothe device 100 by electrical contacts 354 a, 354 b which, respectively,are in contact with electrical conduits 306A, and 306B, which travelthrough an inner thermal and electrical insulation layer 356. An innerthermal and electrical insulation layer 356, and an outer insulationlayer 358, as well as additional insulation layers can be implementedwithin the device to insulate various components against unwantedthermal and electrical coupling. In one embodiment, the device 100 isnormally recharged using solar or thermal means, but when these areinsufficient the patients are alerted 110 so that they can charge thedevice using an external means. In the case of thermal plates 302,304,the patient can apply a heating or cooling device directly to theirskull. In the case of a photovoltaic (i.e. ‘solar’) energy harvester,patients can go outside into the sun or can apply a light (laser) totheir skull.

In FIG. 6A, an extra-cranial receiver plate 350 b which approximatelyconforms to the skull may be used to harness energy using a number ofwireless modalities (e.g., light, temperature, sound, RF induction). Itmay be configured not only with thermal plates 302/304 and a PN stack305, but also with solar components 330, motion-based electricalgeneration components 332 (including sound/vibration harnessingmodules), RF components 334, and/or magnetic induction components 336.The receiver plate 350 b may comprise one or more skull mountedinduction coils, skull-mounted RF antennas, photovoltaic cells, and thelike. Utilization of an extra-cranial receiver plate 350 b, providesenergy harvesting which is more efficient than systems which requirethat radiant energy travel an increased amount of distance, and throughboth skull and tissue, in order to reach receivers locatedintra-cranially. In one embodiment, the device 100 is normally rechargedusing solar or thermal means, but when these are insufficient thepatients are alerted 110 so that they can charge the device using anexternal means. In the case of an RF or magnetic induction receiver, thepatients can act so that the wireless energy transmitter is turned on orbrought into sufficient proximity to the receiver 334, 336. The use ofskull mounted receiver plates 350 a is advantageous because these can belarger than that which might exist when positioned in other parts of thebrain or body. Accordingly receiver plate 350 b as well as arechargeable power supply 10 a capable of energy harnessing, conversion,and storage of energy can be located distal from the ferrule 352 ordevice 100, and can send energy to the device 100 via electricalconduits 306C, 306D. For example, a skull mounted photovoltaic devicethat retained within a distally located receiver plate 350 c (similar tothat seen in FIG. 7), which resides upon a patient's frontal skullportion (i.e. ‘forehead’) is well positioned to receive light and mayreside across a 1 inch by 1-2 inches area without causing the patientdiscomfort. The ferrule 352 is configured for residing in a surgicallyprepared area 351 of the patient's skull 353.

In the case where the receiver plate 350 b serves as an inductionharvester, it may be divided into at least a first portion and a secondportion, each of which may be electrically and thermally insulated fromeach other, which may make functional (data or power) communication withexternal devices (and appropriate polarities) and which may further makerespective electrical connection with skull mounted components, or aferrule which communicates with the device, or at least one implanteddevice itself.

Energy harvesting circuits and antenna's can be configured to receive RFenergy, or wireless energy which has positive and negative chargepolarities. When these components are encased within a metal such astitanium (i.e. when these are within the housing of an implanteddevice), this encasement may be designed with partitioning,non-conductive, and insulating materials which are disposed within thehousing material so as to permit differential charges to be induced onthe energy harvesting circuits and antenna's (i.e. in order tocircumvent or attenuate field dispersion and isopotential surfaces).Alternatively, the receivers may be independently housed and connectedto the implanted device in a manner which enables electrical isolationso that shorting, grounding, and isopotential gradients do not hinderwireless charging functionality.

FIG. 6B shows an embodiment of the invention in which a thermoelectricmodule 300 and device 100 are disposed in an adjacent horizontalconfiguration. Energy can be created when the thermoelectric moduleexperiences a temperature differential between the a first element 304which is on the ventral side and which obtains heat from intracranialsources, and a second element 302, which is disposed dorsally and whichcan further distribute heat along the energy reception plate 350C.Charge crossing the PN stack 305 causes current to flow throughconductive conduits 306A, 306B an into the device 100 through electricalcontacts 354 a,354 b. The PN stack 305 can consist of a multiplicity ofn-doped/p-doped thermocouple pairs preferably electrically arranged inseries and sandwiched between ceramic plates, although any configuringis possible (e.g., U.S. Pat. No. 6,207,887, but which use differentseparator elements between the P-type and the N-type elements. Thus,e.g., one may utilize epoxy-impregnated paper isolators; see, e.g., U.S.Pat. Nos. 3,780,425 and 3,781,176). Alternatively, if the devicesupplies current to the thermoelectric module 300, rather than receivingit, then it can produce heating or cooling of the first and secondelements 304,302, depending upon the characteristics of the currentflow. In this case the device 100 may produce heat, due to discharge ofthe battery in order to provide the thermal stimulation (i.e. cooling orheating of the brain). Energy reception plate 350 d can be configured totransfer heat away from the device 100. Alternatively energy receptionplate 350D can be configured to provide additional forms of wirelessenergy harvesting and can contain some or all of the necessarycomponents to achieve this (although not shown, electrical conduits 306C-E, and electrical contacts 354C-E can provide power and communicationto be exchanged between energy receiver plate 350 d and the device 100).Additionally, energy reception plate 350C can be configured to harnesswireless energy and to supply energy to the thermal module in order toprovide, for example, cooling of the brain.

FIG. 7 shows a rechargeable power supply 10 which is used for recharginga battery, for providing energy to a device 10, or for providing energyduring thermal cooling of the brain which is disposed partially or fullyin an extra-cranial location that is remote from a implanted device 10which here is a neurostimulator. Energy harvesting and recharging aswell as cooling-based neurostimulation therapy can produce heat as aby-product. Further, the discharge of a battery which is supplying powerduring thermal stimulation (i.e. neural-cooling) can result in heatgeneration within the battery. Deployment of the re-charging receiverplates 350 c upon the patient's skull and otherwise removed somewhatfrom the device itself is advantageous since implanted devices often usethe device “can” as a ground to which electrical sensors are referenced.Because charging operations may encounter relatively large fluctuationsin power generation and storage, as well as thermal fluctuations, theseshould likely occur some distance from the device 10 itself.

FIG. 7 shows an embodiment of the invention in which a distally locatedwireless energy receiver module 350C, may be configured as an energyharvesting device 300, 330-336, which contains a signal routing module114 b, for transmitting data and power through electrical conduits 306,and to device 100. When the energy harvesting device is a thermoelectricmodule 300, then energy can be created when the thermoelectric moduleexperiences a temperature differential between its first element 304which is on the ventral side and which obtains heat from intracranialsources, and a second element 302, which is disposed dorsally. Chargecrossing the PN stack 305 causes current to flow through conductiveconduits 306 an into the device 100 through electrical contacts housedunder the electrical connection module 365. Electrical connection modulealso serves to connect a proximal side of neuron-stimulation leads 366to the device 100, so that the distal side can be fed through burr hole367 and into the brain of the patient. The device 100 may reside withina ferrule 352, which has been inserted in a prepared portion of theskull 351, and which is affixed to the skull with connection tabs 370. Afirst device cover 368 and a second device cover 369 can house thedevice components, and can also serve as energy harvesting antenna, orother components of the wireless energy harvesting modules. It isadvantageous to have wireless energy harvesting devices (e.g.thermoelectric charging module) be remote from the neurostimulator sincethese may generate heat or conduct heat in a manner which makes thefirst and second surfaces similar in temperature.

It is one advantage of the current invention to provide anextra-cranially situated power harvester and/or rechargeable powersupply which powers an intra-cranially situated, or skull mounted,device 100 which may be a neurostimulator. In a preferred embodiment, aportion of the recharging power related components are situated at least0.5 inches away from the implanted device.

RF Wireless Energy Transmission and Reception Strategies.

Generally, the power received decreases with the amount of distancebetween the wireless transmitter and the receiver. While a skull mountedreceiver plate 352 can assist in energy transfer with neurostimulationelectrodes, when the implanted device is a cardiac-related device suchpreferential disposition of an RF energy receiver such as an antennawill not help much. The transmission of energy, rather than energyreception, can have improved features which can assist in increasingwireless RF energy harvesting. A number of embodiments can serve todecrease the transmission distance and to increase patient compliancewith respect to maintaining adequate charge levels.

In one embodiment the power transmitter can be implemented withinmodified versions of commonly used objects such as furniture. Forexample, a power transmitter can be located within:

-   -   a. a back of a chair and further with the transmitter situated        approximately adjacent to the patient's upper torso;    -   b. a mattress or mattress cover and further with the transmitter        situated approximately adjacent to the patient's upper torso;    -   c. a wearable vest, and further with the transmitter situated        approximately adjacent to the patient's frontal and rear torso        section;    -   d. an article of clothing such as a chest strap, brassier,        wristband, armband, headband, or hat;    -   e. a blanket, blanket cover, or sheet, and further with the        transmitter situated approximately adjacent to the patient's        upper torso; and,    -   f. a seat cushion configured to overlap or be attached to the        back support portion of a chair and further with the transmitter        situated approximately adjacent to the patient's upper torso.

Because it is wasteful to operate these types of power transmitterscontinuously, power transmission may be linked to a sensor which willautomatically toggle the state of the power transmission. For example, awireless power transmitter which is realized within a back of a chairmay further comprise a motion sensor module, a temperature sensormodule, a light sensor module, or a pressure sensor module, any of whichmay be used to determine if an individual (e.g., a patient with animplanted device) is sitting in the chair. The wireless powertransmitter may also contain a sensor module which can receive an RF,sonic, or other signal from an implanted device that it is within thevicinity of the wireless power transmitter so that wireless powertransmission may be initiated. The wireless power transmitter may alsoinclude a timer or real-time clock so that power transmission can occurfor a selected amount of time, a selected amount of time after a patientactivates a sensor module, during specific times of the day, andotherwise in manners that can be programmable and adjustable by thepatient or a medical practitioner.

Although wireless power may be provided using far-field (e.g., RF)energy transmission, the above features can be implemented withtransmission of other forms of wireless energy such as heat, light,induction, near and medium field transmission. In fact, induction typewireless charging is probably better suited for charging implanteddevices if these are close enough to a body surface of the patient.Further, cooling devices may also be utilized in order to assist inthermoelectric power generation.

Wireless energy utilization can be realized by the implantable deviceusing relatively new technologies for receiving the energy. Suchtechnologies are related to inductive and far-field means oftransmission and reception and include transmission by radiofrequencyenergy, thermal energy, sound energy, and other sources radiant energy.Schemes to achieve wireless energy transmission and harvesting isdisclosed in US 2006/0281435 for [power devices using RF energyharvesting], US20060270440 for a ‘power transmission network’ and a setof related disclosures filed by Shearer et al. and Greene et al, andwhich describe technology known as Powercast. The Powercast technologycan be used for both transmission and reception (harvesting) oftransmitted energy or of ambient energy such as radio-wave energy whichis present in the devices environment. The Powercast technology cancapture wireless energy using both near-field (e.g. inductive) andfar-field transmitters. Alternative transmission-harvesting strategieshave been described with sound or other energy types (e.g., U.S. Pat.No. 6,858,970 for a ‘multi-frequency piezolelectric energy harvester’,US 20050253152 for [Non-contact pumping of light emitters vianon-radiative energy transfer]), or resonant energy harvesterscomprising resonant power antennas which tuned to the powertransmitter's (beacon's) frequency in order to accomplish “nonradiativeresonant energy transfer” (e.g. Soljacic et al. 2006,http://web.mit.edu/newsoffice/2006/wireless.html).

In order for implantable devices to effectively operate using wirelessenergy a number of considerations must be addressed. Firstly, the issueof energy reception should be addressed. When the energy harvestingmodule utilizes antennae larger volumes may be associated with improvedenergy capture. Further, although one energy harvester may be utilized,joint utilization of a plurality of harvesting modules can increase theamount and stability of the supplied power. Implanting the harvestingmodules within the patient should be limited by issues related toimplantation and explanation of the devices, patient comfort, and energyreception. Generally, the deeper implantation results in a correspondingdecrease of energy reception for an equivalent amount of transmittedenergy.

The human skull provides a unique location for implantation of energyharvesting components, including an antenna. In contrast to intracraniallocated positions, the surface of the skull provides a relatively largesurface on which device components may reside. A skull mounted energyharvesting module has a number of benefits such as increased heatdissipation, increased energy transfer due to less intervening tissue,and increased capacity for retaining larger components. A preferredembodiment, skull mounted energy harvesting components may be configuredaccording to the contours of a particular patient's skull, can beconstructed in a flexible manner so that these may bend to the shape ofthe skull, or may be constructed in sections that are flexibly heldtogether and which permit cooperation with the contour of the skull. Theskull mounted energy harvesting device components can reside within aflexible and biocompatible material such as a silicone based sealant, orthe like (Medtronic 20060184210 entitled explanation of implantablemedical device). In another embodiment, an implantable orintra-cranially residing neurostimulator is powered by anextra-cranially and approximately skull mounted harvesting device. Inanother embodiment, an implantable or intra-cranially residingneurostimulator is powered by a cranially residing skull mountedharvesting device, which may be affixed directly within the skull orindirectly via a ferrule device. Two or more energy harvesting devices,or related antennae, may be mounted bilaterally, over opposinghemispheres or split between frontal and posterior locations. The two ormore antennae may be related to different uses such as wirelesstransmission/reception of data and power, respectively. Antennae mayconsist of various electroconductive harnessing substances such asmetal, water, saline, saline laced with metallic flakes, or othersuitable medium.

In one embodiment, recharging is halted or adjusted when non-chargingoperations such as sensing or stimulation operation are to occur. Duringsensing, this may be done in part to reduce any distortion of the sensedsignals. For example, if the ‘can’ is serving as a ground for amono-polar electrode, then if sensing occurs simultaneously withcharging operations then the energy fluctuations associated withcharging operations could distort, contaminate, or otherwise shift therecorded potentials.

For this reason, or due to other considerations, the implanted devicecould be triggered to send control commands to the wireless powerharvester modules to turn energy harvesting ‘on’ or ‘off’. Alternativelyand additionally, the implanted device could send control commands tothe wireless power transmitter to turn energy transmission ‘on’ or‘off’, or can request that energy transmission be temporarily decreasedor increased, or otherwise adjusted. Rather than simply shutting off, atemporarily increase or decrease can occur as a specified ramp-down orramp-up function which may be related to charging operations or directpower supply to a in implanted device. Further, there can exist a“sleep” function which causes the power transmission to be stopped for apre-defined amount of time before it is automatically restarted. In thismanner, energy is not wasted by requiring the implanted device or theexternal patient programmer to send a ‘restart’ signal.

Rather than requiring the implanted device to send commands directly toa wireless power transmission device, the implanted device can controlthe wireless power transmitter indirectly through the external patientcontroller, which can be configured to communication with the powertransmitter as well as the implanted device. Additionally the externalpatient controller can be configured to send control signals to thewireless power transmitter in order to alter its activity, so that itmay better perform its own operations. For example, the external patientcontroller can send control signals to the wireless power transmitterbefore it initiations communication with the implanted device or sendscommands to the implanted device to initiate operations requiringstimulation or sensing. Rather than requiring wireless power companiesto provide specialized transmitters that can receive commands from anexternal patient device, the wireless power transmitter can be power bya mains source which is fed to it by a programmable power supply createdby a medical device manufacturer. Accordingly, an wireless powertransmitter can be used, and a level of control can be obtained bycontrolling the power fed to the transmitter itself.

In one embodiment, the implanted device can provide alerts and statusindications for level and power related characteristics such as theamount of power recently obtained, present power levels, or presentstrength of reception. Alternatively, or additionally the externalpatient programmer can also be configured with a wireless powerharvester and/or ‘power monitor’ module adapted to measure the strengthof transmitted energy that is being received, the amount of energy beingharvested, or an energy profile which can contain an estimation ofenergy present at different wavelengths (e.g. a spectral profile ofenergy). Although the energy implanted wireless power components andexternal wireless power components may receive different amounts ofenergy, “Eint” and “Eext”, respectively, these two amounts can becompared and a transfer function can be used to estimate the amount ofenergy actually received by the implanted harvester.

Additionally, the external patient controller can contain a “powerprofile” module which can adjust the amount of remaining “estimatedpower” for the implantable device by subtracting power which itestimates the internal device is consuming based upon the basal rate ofenergy usage of the device, notices it obtains from the implanted devicethat it has performed operations such as stimulating, and commands sentto the implanted device by the external device such as commands relatedto changing power state (e.g. going into a sleep state or commands toinitiate stimulation or sensing operations).

Although the implanted wireless power harvester module may operate in afixed manner, it may also adjust the characteristics of the harvestermodule in order to generate power from different frequencies of wirelessenergy which are present. The energy reception parameters can beadjusted to bias the reception of frequency specific energy so thatreception of selected frequency ranges are facilitated or blocked. Theenergy harvester can utilize reception parameters which can be adjustedto match the frequencies of the energy which is received with theprofile of energy being transmitted by a wireless power transmitter.This may occur because in different locations, different transmissionprofiles, reception profiles, or transmission-reception profiles willallow energy transmission, harvesting, or both to occur more efficientlyor reliably or to provide different amount of energy as may be requiredby the implanted device. Further, when ambient levels of energy arerelied upon, rather than wireless power transmitted energy, the spectralprofile of the ambient energy may change over time and in differentlocations. Although the implanted device may automatically adjust theparameter of its harvesting module (which may occur with changes in theenergy transmitting module) in order to adjust (i.e. improve) energyharvesting operations, this may require energy and could resulttemporary energy decreases (e.g. if a unsuccessful profile is selected).Accordingly the external patient programmer may perform theseoptimization/calibration processes and then use the results of theseoperations to adjust the characteristics of the implanted energyharvester.

Calibration test-signal procedures can be implemented when normal energyharvesting is not occurring. Additionally, in addition to using theexternal patient controller, an energy monitoring device (or only asensor component) may be worn as a watch, or, in the case of aneurostimulator, can be incorporated into a person's hat or eyeglassesin order to sense energy fields which are similar to that which will beexperienced by the implanted device.

Energy profile sensing can occur within the implanted or external energymonitoring devices in order to adjust parameters related to energyharvesting and increase or stabilize energy reception. While radiowavesmay often be a main source of energy for the wireless power harvesterdevice, if a patient is located in an area with larger sources ofenergy, then the wireless power harvester should be adjustedaccordingly. For example, Extremely low frequency (ELF), voice frequency(VF), and very low frequency (VLF) may be ambient in an environment athigher levels than radiofrequency. Such an example occur in the casewhere a patient is situated in front of a television, so that 50 or 60Hz line noise, and possibly the refresh rate of television screen, aswell as the subharmonics and harmonics will be larger than radio-waveenergy. At least one component of the energy harvester module should beconfigured to capture this type of energy and its harmonics. If thepatient is outdoors in the country, then radiowaves may be larger thansources of 60 Hz, and the receiver should be tuned to optimize captureof this different energy profile. Additionally, the wireless powerharvester module may contain two different harvesting circuits (e.g.including antennae and resonators) which are both active so that energycan be harvested at these very different locations of theelectromagnetic spectrum.

The entire disclosure of all cited references including United Statespatents, applications, websites, and technical/scientific/engineeringpublications are hereby incorporated by reference into thisspecification as if fully recited herein. Using similar design featuressuch as electrical or optical connections will be obvious to thoseskilled in the art, and it will also be obvious to those skilled in theart that the wireless power generation modules and process describedherein may be scaled either up or down in size to suit powerrequirements of specific implantable devices. Any of the aforementionedchanges may be made in the apparatus without departing from the scope ofthe invention as defined in the claims.

All section titles are provided for convenience and are merelydescriptive and thereby are not intended to limit the scope of theinvention.

I claim:
 1. A cranially disposed wireless energy harvester systemcomprising: a rechargeable power storage; a power charging moduleconfigured for charging the rechargeable power storage, said chargingmodule containing at least one first receiver component which is anextra-cranially disposed receiver plate component that is configured forwireless energy harvesting and which serves as part of electricitytransducer circuitry, the receiver plate component located external tothe housing of an implanted medical device; the power charging modulefurther having electrical routing configured to connect with aconnection module in the housing of the implanted medical device, theconnection module configured for receiving wired signals related topower harvesting and transmitting these to components within the housingof the implanted medical device; and, a control subsystem configured forcontrolling electricity generating operations, including those of theelectricity generating circuit, the controlling including haltingwireless energy harvesting at the cranially disposed wireless energyharvester contingently based upon an operation of the implanted medicaldevice that is related to patient monitoring and the provision oftherapy.
 2. The cranially disposed wireless energy harvester system ofclaim 1 wherein said electricity transducer circuit provides energyharvesting which is accomplished using at least two different inductioncoils which are designed to harness energy from two different locationsof the electromagnetic spectrum configured within the first receivercomponent.
 3. The cranially disposed wireless energy harvester system ofclaim of 1, further including a ferrule, and wherein the first receivercomponent is located in an extracranial location that is distinct fromthe location of a device which is being charged and is configured to besecured to the scalp with the ferrule.
 4. The cranially disposedwireless energy harvester system of claim 1, wherein said connectionmodule in the housing of an implanted medical device is configured to beelectrically isolated from the housing of the implanted medical device.5. The cranially disposed wireless energy harvester system of claim 1further including a power monitor configured to monitor power harvestingoperations and to provide a signal if the energy harvested during powerharvesting is less than an amount, wherein the signal is a signal thatis communicated to an external device.
 6. The cranially disposedwireless energy harvester system of claim 1 wherein the therapyoperation of said device is an operation related to sensing data from apatient.
 7. The cranially disposed wireless energy harvester system ofclaim 1 wherein said therapy operation of said device comprises at leastone type of a stimulation operation.
 8. The cranially disposed wirelessenergy harvester system of claim 1, further including an external deviceconfigured to communicate both with the implanted device and with awireless power transmitter, wherein the control subsystem is furtherconfigured to use a communication system to communicate with an externaldevice, which in turn, communicates with a power transmitter in order tocontrol power transmission.
 9. The cranially disposed wireless energyharvester system of claim 1 wherein said therapy operation of saiddevice comprises alerting a patient.
 10. The cranially disposed wirelessenergy harvester system of claim 1 wherein halting power harvestingcomprises halting power harvesting for a selected duration, and thenautomatically restarting power harvesting after the duration hasexpired.
 11. The cranially disposed wireless energy harvester system ofclaim 1 wherein the rechargeable power supply resides within the housingof a neurostimulator, said neurostimulator being configured to receivewired-based power recharging sent using said electrical routing.
 12. Thecranially disposed wireless energy harvester system of claim 1 whereinthe electricity circuit is configured for thermal energy harvesting. 13.The cranially disposed wireless energy harvester system of claim 12,wherein the harvester system includes part of a thermoelectric powergenerator, having a second receiver plate component locatedintra-cranially and a PN stack located between the first and secondreceiver plates, wherein said thermoelectric power generator isconfigured to transduce electricity from a thermal gradient which mayoccur between said first receiver plate component and said secondreceiver plate component.
 14. The cranially disposed wireless energyharvester system of claim 12, wherein said first component iselectrically coupled to a ferrule said ferrule being configured with atleast one of the following: electrical contacts configured tocommunicate electricity to the implanted medical device which isconfigured to receive power from a power harvesting circuit; and asecond receiver plate component configured to reside at an intracraniallocation.
 15. The cranially disposed power harvester system of claim 1wherein the electricity circuit is configured for harvesting byinductive coupling.
 16. The cranially disposed power harvester system ofclaim 1 wherein the electricity circuit is configured for RF energyharvesting.
 17. The cranially disposed power harvester system of claim 1wherein the electricity circuit is configured for resonance energyinductive coupling.